qt 5.15.2 主窗体事件及绘制功能

显示主窗体效果图如下所示：
在这里插入图片描述

main.cpp

#include "mainwindow.h"#include <QApplication>int main(int argc, char *argv[])
{QApplication a(argc, argv);MainWindow w;w.setFixedWidth(600);w.setFixedHeight(600);w.show();//w.showMaximized(); //最大化显示后，再添加布局部件return a.exec();
}

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H#include <QMainWindow>QT_BEGIN_NAMESPACE
namespace Ui {
class MainWindow;
}
QT_END_NAMESPACEclass MainWindow : public QMainWindow
{Q_OBJECTpublic:MainWindow(QWidget *parent = nullptr);~MainWindow();//void print(QString msg);void DrawBorad();void DrawTipText();void PrintMsg(int x,int y,QString msg);void line(int x1,int y1,int x2,int y2);void circle(int x,int y,int radius);//qt 绘制事件void paintEvent(QPaintEvent *event);//qt mouse eventvoid mousePressEvent(QMouseEvent *event);void mouseReleaseEvent(QMouseEvent *event);void mouseMoveEvent(QMouseEvent *event);void keyPressEvent(QKeyEvent *event);void wheelEvent(QWheelEvent *event);void resizeEvent(QResizeEvent *event);//void DrawPiece();private:Ui::MainWindow *ui;    bool isMousePressed=false;QPoint currentPoint;char Current_piece='O';//初始化char Board_piece[3][3]={{'_','_','_'},{'_','_','o'},{'_','_','x'}};
};
#endif // MAINWINDOW_H

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <qpainter.h>
#include <iostream>
#include <QDebug>
#include <QMouseEvent>
#include <QKeyEvent>
#include <QWheelEvent>
#include <QResizeEvent>MainWindow::MainWindow(QWidget *parent): QMainWindow(parent), ui(new Ui::MainWindow)
{ui->setupUi(this);//mouse move event setup must two line OKthis->setMouseTracking(true);ui->centralwidget->setMouseTracking(true);//
}MainWindow::~MainWindow()
{delete ui;    
}void MainWindow::print(QString msg)
{qDebug()<<msg;//std:cout<<msg.toStdString()<<std::endl;
}void MainWindow::DrawBorad()
{line(0,200,600,200);   //cline(0,400,600,400);   //dline(200,0,200,600);  //aline(400,0,400,600);   //b
}void MainWindow::line(int x1,int y1,int x2,int y2)
{QPainter painter(this);painter.drawLine(x1,y1,x2,y2);
}void MainWindow::circle(int x,int y,int radius)
{QPainter painter(this);painter.drawEllipse(QPoint(x,y),radius,radius);
}void MainWindow::DrawTipText()
{QPainter painter(this);//static TCHAR str[64];//_stprintf_s(str,_T("当前棋子类型:%c"),Current_piece);//settextcolor(RGB(255,175,45));//outtextxy(0,0,str);QPen pen;pen.setWidth(2);//设置线宽pen.setStyle(Qt::SolidLine);//样式pen.setColor(QColor(255,0,0));//文字颜色painter.setPen(pen);QString msg=QString::asprintf("当前棋子类型:%c",Current_piece);painter.drawText(10, 15, msg);//文本内容
}void MainWindow::PrintMsg(int x,int y,QString msg)
{QPainter painter(this);//static TCHAR str[64];//_stprintf_s(str,_T("当前棋子类型:%c"),Current_piece);//settextcolor(RGB(255,175,45));//outtextxy(0,0,str);QPen pen;pen.setWidth(2);//设置线宽pen.setStyle(Qt::SolidLine);//样式pen.setColor(QColor(255,45,100));//文字颜色painter.setPen(pen);painter.drawText(x, y, msg);//文本内容
}void MainWindow::DrawPiece()
{for(int i=0;i<3;i++){for(int j=0;j<3;j++){switch(this->Board_piece[i][j]){case 'O':case 'o':this->circle(200*j+100,200*i+100,100);break;case 'x':case 'X':{int x=200*j;int y=200*i;line(x,y,x+200,y+200);   //左对角线(x,y)-(x+100,y+100)line(x+200,y,x,y+200);   //右对角线(x+100,y)-(x,y+100)}break;case '_':case '-':break;}}}
}//总绘制事件
void MainWindow::paintEvent(QPaintEvent *event)
{QPainter painter(this);//反走样painter.setRenderHint(QPainter::Antialiasing, true);//画背景图QString jpgPath="E:\\cwgis_qt\\hsg\\qi_three_son\\images\\china_hdz.jpg";painter.drawPixmap(0,0, 600, 600, QPixmap(jpgPath));//定义画笔QPen pen;pen.setWidth(2);//设置线宽pen.setColor(QColor(222,255,55));//颜色pen.setStyle(Qt::SolidLine);//样式//画刷QBrush brush;brush.setColor(Qt::black);//颜色brush.setStyle(Qt::SolidPattern);//样式//设置画笔画刷painter.setPen(pen);painter.setBrush(brush);//画直线painter.drawLine(50,50,150,50);painter.drawLine(20,50,250,150 );//画矩形painter.drawRect(70,200,100,50);//画椭圆painter.drawEllipse(QPoint(270,150),50,80);//画文字QFont font;font.setFamily("MV Boli");//文字字体font.setPixelSize(20);//文字大小pen.setColor(QColor(255,55,255));//文字颜色painter.setFont(font);painter.setPen(pen);painter.drawText(200, 300, "Qt Creator 12.0.0 (opensource)");//文本内容//this->DrawBorad();this->DrawPiece();//this->DrawTipText();this->PrintMsg(20,30,jpgPath);this->PrintMsg(20,40,qApp->applicationDirPath());  //获取可执行文件所在目录//{QString msg=QString::asprintf("%d,%d",this->currentPoint.x(),this->currentPoint.y());this->PrintMsg(40,580,"(x,y)="+msg);}
}void MainWindow::mousePressEvent(QMouseEvent *event)
{this->isMousePressed=true;print("pressed mouse");this->update();
}
void MainWindow::mouseReleaseEvent(QMouseEvent *event)
{this->isMousePressed=false;print("unpresse mouse");this->update();
}void MainWindow::mouseMoveEvent(QMouseEvent *event)
{QPoint p=event->pos();this->currentPoint=p;qDebug()<<"pos="<<p;   //需要引用#include <QMouseEvent>//QString msg=QString::asprintf("%d,%d",p.x(),p.y());//this->PrintMsg(40,300,"(x,y)="+msg);//qDebug()<<msg;if(this->isMousePressed){QString msg=QString::asprintf("%b",this->isMousePressed);this->PrintMsg(570,40,"isMousePressed="+msg);}else{QString msg=QString::asprintf("%b",this->isMousePressed);this->PrintMsg(570,40,"isMousePressed="+msg);}print("moveing mouse");this->update();   //更新触发重绘事件paintEvent 才能动态显示当前点坐标(x,y)=100,200
}void MainWindow::keyPressEvent(QKeyEvent *event)
{qDebug()<<"key: "<<event->key();this->update();
}
void MainWindow::wheelEvent(QWheelEvent *event)
{qDebug()<<"wheel: "<<event->angleDelta();this->update();
}void MainWindow::resizeEvent(QResizeEvent *event)
{qDebug()<<"resize: "<<event->size();this->update();
}